Java Helpers类代码示例

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
Set<Feature<?>> computeMultimapGetFeatures(Set<Feature<?>> multimapFeatures) {
  Set<Feature<?>> derivedFeatures = Helpers.copyToSet(multimapFeatures);
  for (Map.Entry<Feature<?>, Feature<?>> entry : GET_FEATURE_MAP.entries()) {
    if (derivedFeatures.contains(entry.getKey())) {
      derivedFeatures.add(entry.getValue());
    }
  }
  if (derivedFeatures.remove(MultimapFeature.VALUE_COLLECTIONS_SUPPORT_ITERATOR_REMOVE)) {
    derivedFeatures.add(CollectionFeature.SUPPORTS_ITERATOR_REMOVE);
  }
  if (!derivedFeatures.contains(CollectionFeature.SERIALIZABLE_INCLUDING_VIEWS)) {
    derivedFeatures.remove(CollectionFeature.SERIALIZABLE);
  }
  derivedFeatures.removeAll(GET_FEATURE_MAP.keySet());
  return derivedFeatures;
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
@MapFeature.Require(SUPPORTS_REMOVE)
@CollectionSize.Require(absent = ZERO)
public void testRemovePropagatesToAsMap() {
  List<Entry<K, V>> entries = Helpers.copyToList(multimap().entries());
  for (Entry<K, V> entry : entries) {
    resetContainer();

    K key = entry.getKey();
    V value = entry.getValue();
    Collection<V> collection = multimap().asMap().get(key);
    assertNotNull(collection);
    Collection<V> expectedCollection = Helpers.copyToList(collection);

    multimap().remove(key, value);
    expectedCollection.remove(value);

    assertEqualIgnoringOrder(expectedCollection, collection);
    assertEquals(!expectedCollection.isEmpty(), multimap().containsKey(key));
  }
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
public void testArbitrary_withCollisions() {
  List<Integer> list = Lists.newArrayList();
  for (int i = 0; i < 50; i++) {
    list.add(i);
  }

  Ordering<Object> arbitrary = new ArbitraryOrdering() {
    @Override int identityHashCode(Object object) {
      return ((Integer) object) % 5; // fake tons of collisions!
    }
  };

  // Don't let the elements be in such a predictable order
  list = shuffledCopy(list, new Random(1));

  Collections.sort(list, arbitrary);

  // Now we don't care what order it's put the list in, only that
  // comparing any pair of elements gives the answer we expect.
  Helpers.testComparator(arbitrary, list);
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
@MapFeature.Require(SUPPORTS_PUT)
@CollectionSize.Require(absent = ZERO)
public void testPutPresentKeyPropagatesToAsMapGet() {
  List<K> keys = Helpers.copyToList(multimap().keySet());
  for (K key : keys) {
    resetContainer();

    int size = getNumElements();

    Collection<V> collection = multimap().asMap().get(key);
    assertNotNull(collection);
    Collection<V> expectedCollection = Helpers.copyToList(collection);

    multimap().put(key, v3());
    expectedCollection.add(v3());
    assertEqualIgnoringOrder(expectedCollection, collection);
    assertEquals(size + 1, multimap().size());
  }
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
@CollectionSize.Require(SEVERAL)
public void testOrderingDoesntAffectEqualsComparisons() {
  SetMultimap<K, V> multimap1 =
      getSubjectGenerator()
          .create(
              Helpers.mapEntry(k0(), v0()),
              Helpers.mapEntry(k0(), v1()),
              Helpers.mapEntry(k0(), v4()));
  SetMultimap<K, V> multimap2 =
      getSubjectGenerator()
          .create(
              Helpers.mapEntry(k0(), v1()),
              Helpers.mapEntry(k0(), v0()),
              Helpers.mapEntry(k0(), v4()));
  new EqualsTester().addEqualityGroup(multimap1, multimap2).testEquals();
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
@SuppressWarnings("unchecked") // dang varargs
public void testLexicographical() {
  Comparator<String> comparator = Ordering.natural();
  Comparator<Iterable<String>> lexy = Comparators.lexicographical(comparator);

  ImmutableList<String> empty = ImmutableList.of();
  ImmutableList<String> a = ImmutableList.of("a");
  ImmutableList<String> aa = ImmutableList.of("a", "a");
  ImmutableList<String> ab = ImmutableList.of("a", "b");
  ImmutableList<String> b = ImmutableList.of("b");

  Helpers.testComparator(lexy, empty, a, aa, ab, b);

  new EqualsTester()
      .addEqualityGroup(lexy, Comparators.lexicographical(comparator))
      .addEqualityGroup(Comparators.lexicographical(String.CASE_INSENSITIVE_ORDER))
      .addEqualityGroup(Ordering.natural())
      .testEquals();
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
/**
 * Verify thread safety by using a collection whose size() may be inconsistent
 * with the actual number of elements.  Tests using this method might fail in
 * GWT because the GWT emulations might count on size() during copy.  It is
 * safe to do so in GWT because javascript is single-threaded.
 */
// TODO(benyu): turn this into a test once all copyOf(Collection) are
// thread-safe
@GwtIncompatible // GWT is single threaded
void verifyThreadSafe() {
  List<String> sample = Lists.newArrayList("a", "b", "c");
  for (int delta : new int[] {-1, 0, 1}) {
    for (int i = 0; i < sample.size(); i++) {
      Collection<String> misleading = Helpers.misleadingSizeCollection(delta);
      List<String> expected = sample.subList(0, i);
      misleading.addAll(expected);
      assertEquals("delta: " + delta + " sample size: " + i,
          Sets.newHashSet(expected), copyOf(misleading));
    }
  }
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
@Override
public void setUp() throws Exception {
  super.setUp();
  navigableSet = (NavigableSet<E>) getSet();
  values =
      Helpers.copyToList(
          getSubjectGenerator()
              .getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));
  Collections.sort(values, navigableSet.comparator());

  // some tests assume SEVERAL == 3
  if (values.size() >= 1) {
    a = values.get(0);
    if (values.size() >= 3) {
      b = values.get(1);
      c = values.get(2);
    }
  }
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
@CollectionSize.Require(ONE)
@CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
public void testIteratorRemovePropagatesToMultimap() {
  Iterator<Entry<K, V>> iterator = multimap().entries().iterator();
  assertEquals(Helpers.mapEntry(k0(), v0()), iterator.next());
  iterator.remove();
  assertTrue(multimap().isEmpty());
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
public void testLexicographicalComparator() {
  List<double[]> ordered = Arrays.asList(
      new double[] {},
      new double[] {LEAST},
      new double[] {LEAST, LEAST},
      new double[] {LEAST, (double) 1},
      new double[] {(double) 1},
      new double[] {(double) 1, LEAST},
      new double[] {GREATEST, Double.MAX_VALUE},
      new double[] {GREATEST, GREATEST},
      new double[] {GREATEST, GREATEST, GREATEST});

  Comparator<double[]> comparator = Doubles.lexicographicalComparator();
  Helpers.testComparator(comparator, ordered);
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
public void testForEachEntry() {
  List<Entry<E>> expected = new ArrayList<>(getMultiset().entrySet());
  List<Entry<E>> actual = new ArrayList<>();
  getMultiset()
      .forEachEntry((element, count) -> actual.add(Multisets.immutableEntry(element, count)));
  Helpers.assertEqualIgnoringOrder(expected, actual);
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
public void testArbitrary_withoutCollisions() {
  List<Object> list = Lists.newArrayList();
  for (int i = 0; i < 50; i++) {
    list.add(new Object());
  }

  Ordering<Object> arbitrary = Ordering.arbitrary();
  Collections.sort(list, arbitrary);

  // Now we don't care what order it's put the list in, only that
  // comparing any pair of elements gives the answer we expect.
  Helpers.testComparator(arbitrary, list);

  assertEquals("Ordering.arbitrary()", arbitrary.toString());
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
@MapFeature.Require(SUPPORTS_PUT)
@CollectionSize.Require(absent = ZERO)
public void testPutPresentKeyPropagatesToAsMapEntrySet() {
  List<K> keys = Helpers.copyToList(multimap().keySet());
  for (K key : keys) {
    resetContainer();

    int size = getNumElements();

    Iterator<Entry<K, Collection<V>>> asMapItr = multimap().asMap().entrySet().iterator();
    Collection<V> collection = null;
    while (asMapItr.hasNext()) {
      Entry<K, Collection<V>> asMapEntry = asMapItr.next();
      if (key.equals(asMapEntry.getKey())) {
        collection = asMapEntry.getValue();
        break;
      }
    }
    assertNotNull(collection);
    Collection<V> expectedCollection = Helpers.copyToList(collection);

    multimap().put(key, v3());
    expectedCollection.add(v3());
    assertEqualIgnoringOrder(expectedCollection, collection);
    assertEquals(size + 1, multimap().size());
  }
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
public void testLexicographicalComparator() {
  List<long[]> ordered = Arrays.asList(
      new long[] {},
      new long[] {MIN_VALUE},
      new long[] {MIN_VALUE, MIN_VALUE},
      new long[] {MIN_VALUE, (long) 1},
      new long[] {(long) 1},
      new long[] {(long) 1, MIN_VALUE},
      new long[] {MAX_VALUE, MAX_VALUE - (long) 1},
      new long[] {MAX_VALUE, MAX_VALUE},
      new long[] {MAX_VALUE, MAX_VALUE, MAX_VALUE});

  Comparator<long[]> comparator = Longs.lexicographicalComparator();
  Helpers.testComparator(comparator, ordered);
}
 

import com.google.common.collect.testing.Helpers; //导入依赖的package包/类
public void testToArray_threadSafe() {
  for (int delta : new int[] { +1, 0, -1 }) {
    for (int i = 0; i < VALUES.length; i++) {
      List<Long> list = Longs.asList(VALUES).subList(0, i);
      Collection<Long> misleadingSize =
          Helpers.misleadingSizeCollection(delta);
      misleadingSize.addAll(list);
      long[] arr = Longs.toArray(misleadingSize);
      assertEquals(i, arr.length);
      for (int j = 0; j < i; j++) {
        assertEquals(VALUES[j], arr[j]);
      }
    }
  }
}